Externally-defined, arrival-sequence file - getting to the last record

Hi All,
 
How does one get to the last record of an externally-defined, arrival-sequence 
(i.e., no keys) file without reading thru every record?  I want to start the 
program, then immediately hit the end-of-file, then wait for a new record to 
appear.  (I know about overriding the file with EOFDLY(nnn) for this to work.)
 
I added the RECNO(rrn) keyword to the file definition, set rrn=*hival and tried 
using 
 
CHAIN (rrn) Filename and 
SETGT (rrn) Filename.
 
I keep getting compile error messages saying "key field list not allowed with 
program described file".
 
I have the file defined as an input, full procedural, externally-described disk 
file with a blank record address type and a RECNO keyword. To me, that makes 
this a file to be processed by relative record number.
 
Where am I going wrong?????  Ideas???  (I haven't had to deal with relative 
record number processing outside of subfiles since my S/34 Mapics days fresh 
out of school!)
 
Many thanks in advance,
 
William